1. Field of the Invention
The present invention relates to a golf club head having a weight distributing system and more particularly, to a wood type golf club head having an integrally formed steel ball within the club head cavity so as to have improved performance characteristics resulting from strategic changes in weight dispensation of the steel ball.
2. Description of Related Art
Several types of golf club heads having a movable weight therein such as golf club drivers are known in the art.
Golf is a game which requires exacting techniques to achieve a proper swing. One aspect of a proper swing relates to the swing plane which is the plane in which club should substantially move during a swing. The basic determinative factors with regard to the position of a golfer's swing plane is his or her physical stature and his or her address posture. The more a golfer bends over the ball from the waist at address, and the closer he sets his hands to his body, the more upright becomes the plane in which he naturally tends to swing. Conversely, short golfers tend to swing in a flatter plane, i.e. a less upright plane, than tall golfers because their lack of height in relation to the standard length of club shafts forces them to stand farther from the ball. The swing plane also shifts between different clubs because of differences in their relative lengths.
Another important aspect of a proper golf swing is the desirability that the head of the club strike the ball at that point of the golf swing where the club head velocity is the greatest and that such speed be maintained into the follow-through. Maximum force of impact between the club face and the ball is obtained without the club head torquing when the ball is hit in the "sweet spot" of the club head face. The sweet spot is typically located at the center of the club face and has been thought of as the location on the club face directly forward of the center of gravity of the club head. For example, a golfer may locate the sweet spot of a putter by holding it lightly between the thumb and forefinger at the top end of the grip and then gently tap the face of the putter head with an object such as a ball at different locations on the club face until the club head recoils straight back and forth like a pendulum without twisting or torquing off-line.
Accordingly, this approach does locate the sweet spot of the club while essentially at rest. However, as the club is fully swung, often in various swing planes due to swing inconsistencies of golfers of average ability, the sweet spot actually shifts due to redistribution of the mass of the club head with respect to the swing plane where it extends through the club head, and to differences in different speeds of different portions of the club head. Because the sweet spot of a club in motion is determined relative to mass and velocity of the club, it may be referred to as the center of inertia of the golf club. Such shifting of the center of inertia hampers a golfer's ability to make ball contact at the sweet spot. The further a ball is hit from the center of inertia the more it will tend to be misdirected or imparted with a side spin.
It thus is seen that a need remains for a golf club that can substantially maintain its center of inertia or sweet spot in the same location upon the club head regardless of the orientation of the plane in which the club is swung or its velocity. It is to the provision of such therefore that the present invention is primarily directed.
Also, a driver in general has a long shaft that requires a swing to take an arcuate path to meet a ball placed a distance in front of the golfer. Motion over this path introduces a torque during the swing which tends to twist the head position away from a square contact with the ball. Thus, a golfer must develop a swing that controls the club by tempo, speed and grip to address the ball squarely. Accordingly it requires a high degree of skill to address a ball properly with a wood or driver.
Metal wood golf club heads formed by a light weight durable metal shell having a hollow interior currently enjoy a high level of popularity compared with conventional wood type club head designs. Metal wood heads have been known for a number of years, as evidenced by U.S. Pat. No. 1,568,888 and Australian Pat. No. 211,781.
Furthermore, such golf club heads having a weight therewithin disclose U.S. Pat. Nos. 3,951,413, 5,141,230, 5,193,805, and 5,195,747. However, these patents do not disclose the use of a steel ball within a club head cavity for hitting the golf ball behind a front surface so as to improve performances such as a long distance hit, straight ahead accuracy of the golf ball, less effort of a golfer and the like.